1. Field of the Invention
This invention relates generally to press cleaning apparatus and more particularly to such an apparatus which is air-operated, portable, manually manipulatable, and stable, which can be used to clean the lower surfaces of the upper platens of large consolidating presses.
2. Description of the Prior Art
Electrical and air-operated rotary abrading devices are generally well-known. Also well-known are abrading devices of the so-called "disk sander" type wherein the disk is mounted on a drive shaft which extends from the motor at a right angle thereto. It is further known to provide support frames, guides, handles, etc. in combination with such devices, to facilitate their use for abrading, cleaning and buffing many and varying work surfaces.
Typical of the state of the art in the field of concern of the present invention are the disclosures of U.S. Pat. Nos. 3,375,617; 2,507,052; and 2,603,919. These patents disclose surface finishing or abrading apparatus including adjustable support means therefor.
The devices of the prior art do not, however, afford a solution to the problems solved by the apparatus of the present invention.
The apparatus of the present invention is primarily used to clean the lower surfaces of the upper platens of large heated presses used to consolidate thermoplastic granular material. In the use of such presses, some of the material being pressed sticks to the lower surface of the upper platen. Particular trouble is experienced with a build-up of the material at the side edges of the press.
Since the specific presses on which the apparatus of this invention is used are large, and are usually hot when cleaning is required, and since the platens are not normally accessible from the sides due to support beams, power lines, and various necessary equipment, access to the platen must be from one end or the other thereof. This, plus the fact that it is the lower surface of the upper platen which is to be cleaned, makes it desirable to mount the abrasive disk and the drive means therefor on an elongated handle. In such an apparatus, it is further desirable to have the control means for the abrasive disk at a location on the handle which is easily accessible to the operator. Obviously, since the abrasive disk must be pressed against the lower surface of the upper platen, and since the device is manually manipulated, it is important that the disk and drive means not only be supported, but be supported in such a manner that it is movable. Also, the device must be capable of being used to clean the entire lower surface of the upper platen of a press, including all edges thereof, without the support means therefor slipping off the edge of the bottom platen. Further, it is important that even pressure be maintained on the work surface regardless of irregularities on the work surface or on the supporting surface over which the apparatus is being moved. It is further desirable to be able to pivot the apparatus while in use to provide more or less contact of the abrasive disk with the work surface and to be able to control the RPM of the disk easily.